<s>
On	O
IBM	B-Device
mainframes	I-Device
running	O
the	O
z/OS	B-Application
operating	B-General_Concept
system	I-General_Concept
,	O
Intelligent	B-Application
Resource	I-Application
Director	I-Application
(	O
IRD	O
)	O
is	O
software	O
that	O
automates	O
the	O
management	O
of	O
CPU	B-Device
resources	O
and	O
certain	O
I/O	B-General_Concept
resources	O
.	O
</s>
<s>
IRD	O
is	O
implemented	O
as	O
a	O
collaboration	O
between	O
Workload	B-Application
Manager	I-Application
(	O
WLM	O
)	O
,	O
a	O
component	O
of	O
z/OS	B-Application
,	O
and	O
the	O
PR/SM	B-Device
Logical	B-Device
Partitioning	I-Device
(	O
LPAR	B-Device
)	O
hypervisor	B-Operating_System
,	O
a	O
function	O
of	O
the	O
mainframe	B-Architecture
hardware	O
.	O
</s>
<s>
(	O
This	O
does	O
not	O
apply	O
to	O
zIIPs	B-Device
or	O
zAAPs	B-Language
.	O
)	O
</s>
<s>
Weight	O
Management	O
-	O
where	O
IRD	O
dynamically	O
redistributes	O
LPAR	B-Device
weights	O
between	O
members	O
of	O
an	O
LPAR	B-Device
Cluster	O
.	O
</s>
<s>
(	O
An	O
LPAR	B-Device
Cluster	O
is	O
the	O
set	O
of	O
members	O
of	O
a	O
Parallel	B-Operating_System
Sysplex	I-Operating_System
on	O
a	O
single	O
mainframe	B-Architecture
footprint	O
.	O
)	O
</s>
<s>
The	O
total	O
of	O
the	O
weights	O
for	O
the	O
LPAR	B-Device
Cluster	O
remains	O
constant	O
as	O
weights	O
are	O
shifted	O
between	O
the	O
members	O
.	O
</s>
<s>
(	O
Linux	B-Application
on	I-Application
IBM	I-Application
Z	I-Application
LPARs	B-Device
can	O
also	O
participate	O
in	O
Weight	O
Management	O
.	O
)	O
</s>
<s>
CHPID	O
Management	O
-	O
where	O
logical	O
channel	O
paths	O
are	O
moved	O
between	O
members	O
of	O
an	O
LPAR	B-Device
Cluster	O
.	O
</s>
